If you have access to the server back-end, we recommend clearing the Drupal cache through the drush tool as it is faster. However, administrators will not normally have such access, so these instructions will show you how to do it through Drupal. Start by logging into your site and then clicking on “Configuration” in the toolbar (highlighted in red in the below image). Find the link for “Performance” underneath the heading “Development” and click on it (highlighted in green).
This will take you to the Performance page (shown below). Most of the settings on this page should not be touched, for optimal performance. If you would like to clear the cache, click the “Clear all caches” button (highlighted below in orange). Note that this process will take a minute or two to perform and the first few requests to your site may be slow after clicking this button. We do not recommend doing so during times of heavy traffic unless it is necessary.